1. Field of the Invention
This invention relates to hydraulic coupling members. More particularly, it relates to male and female hydraulic coupling members equipped with internal, spring-loaded poppet valves for controlling the flow of hydraulic fluid.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A wide variety of hydraulic couplings include internal poppet valves for preventing the loss of hydraulic fluid when the coupling is disconnected. Hydraulic couplings designed for subsea use also commonly employ poppet valves for preventing seawater from entering the hydraulic system when the coupling members are de-mated. In many designs, the poppet valves include mechanical valve actuators which cause valves that are spring-loaded to the closed position to open upon coupling make-up.
U.S. Pat. Nos. 4,900,071 and 5,052,439 disclose an undersea hydraulic coupling which includes a male member and female member and a two-piece retainer for restraining radial movement of a wedge-shaped annular seal into the central bore of the female member. The two-piece retainer includes a cylindrical retainer sleeve member that slides within the female member bore, and a threaded retainer-locking member which engages threads in the wall of the central bore. The retainer-locking member holds the retainer sleeve member in place within the female member bore. The annular seal is restrained from radial movement by a dovetail interfit with a mating shoulder on at least one of the retainer sleeve and the retainer-locking members.
U.S. Pat. No. 5,360,035 discloses an undersea hydraulic coupling having a poppet valve movable between an open and a closed position. The poppet valve is pressure balanced—i.e., it operates without substantial fluid pressure exerted axially against the face of the poppet valve. When the poppet valve is opened, radial passages are interconnected through an annular cavity between the poppet valve body and the valve bore.
U.S. Pat. No. 5,692,538 discloses an undersea hydraulic coupling member having angled flow ports to prevent ingress of debris into the hydraulic lines and having a bleed passage to allow trapped hydraulic fluid to bleed off when the coupling members are disconnected. The poppet valve in combination with the angled flow ports helps keep the hydraulic system clear of debris when the members are disconnected.
U.S. Pat. No. 6,085,785 discloses an undersea hydraulic coupling having an extended probe section. The male member of the coupling houses a valve spring having a larger diameter than the diameter of the valve body. The valve spring is configured to close the valve to prevent ingress of sea water or leakage of hydraulic fluid from the system. One or more seals engage the extended probe section.
U.S. Pat. No. 6,095,191 discloses an undersea hydraulic coupling having a male member with a tapered, frusta-conical surface and a female member with a tapered, frusta-conical bore. Before radial seals engage the frusta-conical surfaces, trapped seawater is expelled or displaced from the bore through the space between the coupling members, thereby preventing seawater from entering hydraulic lines.
U.S. Pat. No. 6,474,359 discloses an undersea hydraulic coupling member having a bleed valve which opens to allow hydraulic fluid trapped in the coupling member to escape until the pressure is below a predetermined level. The coupling member employs a poppet valve within a sleeve.
U.S. Pat. No. 6,375,153 discloses an undersea hydraulic coupling having a stepped internal bore dimensioned to increase the flow rate through the coupling. The coupling allows an increased flow rate without increasing the size or weight of the coupling by positioning the poppet valve in the body section, rather than in the probe section, of the male coupling member.
U.S. Pat. No. 6,237,632 discloses an undersea hydraulic coupling member having a primary poppet valve and a secondary poppet valve to improve reliability against leakage when the coupling members are separated. A spring extends between the first poppet valve and the actuator for the second poppet valve. The secondary poppet valve remains closed unless the first poppet valve is fully opened, so that debris or other material that could prevent sealing of the first poppet valve will not cause leakage of hydraulic fluid through the second poppet valve.
U.S. Pat. No. 6,357,722 discloses an undersea hydraulic coupling having a poppet valve with an actuator extending from the valve and a guide between the actuator and bore. The guide is a sleeve-shaped member around the actuator with flow passages which ensure a smooth flow of hydraulic fluid through the annulus between the coupling bore and actuator. The guide also helps prevent damage to the actuator, and aligns the actuator during connections, disconnections and use.
U.S. Pat. No. 6,283,444 discloses an undersea hydraulic coupling member having a valve actuator which extends through the probe section and the leading face, and has angled flow ports in the probe section which help keep the hydraulic system clear of debris when the coupling members are disconnected subsea.
U.S. Pat. No. 6,227,245 discloses an undersea hydraulic coupling member which has angled flow ports to prevent ingress of debris into the hydraulic lines. A port guard attached to the valve actuator closes the flow ports unless the poppet valve is opened by mutual engagement with an opposing coupling member.
U.S. Pat. No. 6,626,207 discloses an undersea hydraulic coupling with interlocking poppet valve actuators. The actuators extend from the poppet valves of each coupling member and interlock to resist bending and/or other lateral displacement caused by hydraulic fluid flow and turbulence in the coupling member bores and at the junction between the coupling members.
U.S. Pat. No. 6,631,734 discloses a dummy undersea hydraulic coupling member for protecting an opposing undersea hydraulic coupling member when the hydraulic lines are not operating. The dummy undersea hydraulic coupling member has a water displacement expansion chamber with a piston therein that allows trapped water and/or air to move from the receiving chamber to the water displacement expansion chamber during connection of the dummy coupling member to the opposing coupling member. The dummy coupling member may include a normally-closed poppet valve in the water displacement expansion chamber which blocks water and/or air from moving between the receiving chamber and the water displacement expansion chamber in the closed position. The poppet valve opens in response to water and/or air pressure acting upon it.
U.S. Pat. No. 7,159,616 discloses a dual-path hydraulic coupling. A female hydraulic coupling member comprises a first flow port; a second flow port; a third flow port in fluid communication with both the first flow port and the second flow port; a first poppet valve for opening and closing the first flow port; and a second poppet valve for opening and closing the second flow port, the second poppet valve being connected to the first poppet valve such that the second poppet valve moves to the closed position when the first poppet valve is open and moves to the open position when the first poppet valve is closed.
U.S. Pat. No. 7,913,974 discloses male and female hydraulic coupling members which have an internal poppet valve that is held in the closed position by a flat wire, helical compression spring. The spring is configured such that when the poppet valve is moved to its fully open position, the coils of the spring are completely compressed thereby forming a substantially smooth bore tube for the flow of hydraulic fluid. The flat wire, helical compression spring may also act as a valve stop, limiting movement of the poppet valve and providing the necessary resistance to move the valve actuator of a corresponding valve in a mating member.
In the subsea hydraulic couplings of the prior art, damage can occur when a coupling member is raised from depth due to the change in the differential pressure between the hydraulic fluid within the coupling and the ambient pressure—i.e., the pressure due to the water column and/or atmospheric pressure. The present invention solves this problem.